Meh, was one of those attack Alsatians in COD4. I have two Dogues de Bordeaux and a Neapolitan Mastiff and the Dogues were breed to fight sodding tigers and shit so I'm not worried with over thirty stone of mastiff on my side. And the missus is nasty too.
In fact the GSD would be so scared he'd ask to stay and work off any offence caused. Nobody messes with my dogs(truth be told they never actually fought with anything-but, still, I got told off by the vet for playfighting with Louis, our biggest at fourteen stones because "he can kill you whenever he likes just playing")but I think they'd struggle with Regenerators and stuff like that.